Automatic Wellbore Activity Schedule Adjustment Method and System

ABSTRACT

A method for scheduling wellbore construction activities includes entering a well plan into a computer. The well plan includes estimated start and stop times for a plurality of activities in a predetermined sequence. Progress of selected ones of the plurality of activities is measured during their performance. In the computer, expected ending time of at least one of the plurality of activities is recalculated based on progress thereof during that activity. In the computer, expected start and stop times are recalculated for each activity subsequent to the activity in progress based on the recalculated expected ending time. The recalculated start and stop times for each subsequent activity are displayed.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation application of co-pending U.S. patent applicationSer. No.: 14/535200, filed on Nov. 6, 2014, and entitled “AutomaticWellbore Activity Schedule Adjustment Method and System,” which claimsbenefit of U.S. Provisional Patent Application 61/903418, filed on Nov.13, 2013, and is hereby incorporated in its entirety for all intents andpurposes by this reference.

BACKGROUND

This disclosure relates generally to the field of wellbore drillingoperations ancillary to actions that lengthen (drill) the wellbore. Morespecifically, the disclosure relates to method for providing operatingguidance to drilling unit operating personnel for optimum speed ofmovement of a drill string in and out of a wellbore (“tripping”), andfor collecting and comparing actual tripping measurement data tobenchmark tripping data to evaluate and improve efficiency of particulardrilling unit operating personnel (“crews”).

Wellbore drilling operations include activities ancillary to drillingthe wellbore, including, e.g., tripping a drill string (i.e., assemblyof drill pipe segments as “stands” and/or “joints”) out of the wellboreand back into the wellbore for the purposes, among others, of changingdrill bits or other drilling tools, setting a conduit (e.g., a casing orliner) in the wellbore and circulating drill cuttings out of thewellbore along its entire length.

Tripping may be speed constrained by reason of hydrostatic fluidpressure changes in the wellbore caused by removal of the drill stringfrom the wellbore or insertion of the drill string into the wellbore.Fluid displacement by such movement of the drill string, combined withviscous effects of the drilling fluid (“mud”) in the wellbore may causecorresponding decreases or increases in the hydrostatic pressure of themud. If the hydrostatic pressure is increased by excessive speed“tripping in” (i.e., moving the drill string into the wellbore), it ispossible to exceed fracture pressure of one or more exposed formationsin an uncased part of the wellbore (called “surge”). Conversely,decrease in hydrostatic pressure caused by excessive speed “trippingout” (i.e., removing the drill string from the wellbore) may result inthe hydrostatic pressure being reduced below the formation fluidpressure of some exposed formations (called “swab”). Either of theforegoing may result in a wellbore pressure control emergency situation.

It is well known in the art how to calculate increases and decreases inhydrostatic pressures caused by tripping if the drill stringconfiguration is known and the mud properties (e.g., density, viscosity)are known.

Tripping may also be speed constrained by reason of shock and vibrationof the drill string as it moves through the wellbore. If shock andvibration limits are exceeded for certain drill string components, thenthey may be susceptible to failure during drilling operations.

It is desirable to communicate such information to a drilling unitoperating crew in an easy to use form so that their operating procedurescan be guided and improved. It is also desirable to accumulatestatistical information over a wellbore and in some cases compare tobenchmark operating procedures from other wellbores in order to improvedrilling unit operating crew performance.

There may be differences between an original well plan, which mayinclude a detailed sequence of specific drilling actions and ancillaryactions, and an actual well construction schedule as a result of actionssuch as the foregoing being performed more or less quickly thanoriginally intended, or where the originally planned sequence ofspecific actions is altered as a result of conditions encountered duringwellbore construction. It may be desirable to be able to revise thedetailed sequence to correspond to the actual performance of part of thedetailed sequence and the actual wellbore conditions encountered.

SUMMARY

A method according to one aspect for scheduling wellbore constructionactivities includes entering a well plan into a computer. The well planincludes estimated start and stop times for a plurality of activities ina predetermined sequence. Progress of selected ones of the plurality ofactivities is measured during their performance. In the computer,expected ending time of at least one of the plurality of activities isrecalculated based on progress thereof during that activity. In thecomputer, expected start and stop times are recalculated for eachactivity subsequent to the activity in progress based on therecalculated expected ending time. The recalculated start and stop timesfor each subsequent activity are displayed.

Other aspects and advantages will be apparent from the description andclaims that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example drilling and measurement system.

FIG. 2 shows a block diagram of an example of calculating an expected“trip speed profile” for each stand of pipe in a wellbore.

FIG. 3 shows an example display of the expected trip speed profile andan actual trip speed profile for one stand of pipe.

FIGS. 4A and 4B show two example displays for a stand where the expectedprofile was not followed for the entire stand.

FIGS. 5A and 5B show example displays of time fractions in each ofseveral selected operating conditions for a single stand andcumulatively for each stand in a trip, respectively.

FIG. 6 shows an example block diagram of accumulation of statisticaldata for each stand for a trip and for a wellbore.

FIG. 7 shows a cumulative display with respect to wellbore depth of anexpected speed profile with an actual speed profile overlay.

FIGS. 8A and 8B show, respectively, coded versions of the display inFIG. 6 with codes for the type of deviation from the expected speedprofile, and cumulative statistics for an entire well.

FIG. 9 shows a comparison of a normalized wellbore trip speed profilewith a comparison to nearby wellbore normalized trip speed profiles forwell to well performance comparison.

FIG. 10 shows another type of statistical display used to identifyoperating procedure trends in connection time data.

FIG. 11 shows a block diagram of an example procedure for schedulingother wellbore ancillary operations based on actual drilling time andtripping time with reference to planned drilling time and tripping time.

FIG. 12 shows an example time vs. depth curve to assist the wellboreoperator in calculating delay or advance of any of the operationsdescribed with reference to FIG. 10.

FIG. 13 shows an example computer system on which parts of or all ofmethods according to the present disclosure may be performed.

DETAILED DESCRIPTION

FIG. 1 shows a simplified view of an example drilling and measurementsystem that may be used in some embodiments. The drilling andmeasurement system shown in FIG. 1 may be deployed for drilling eitheronshore or offshore wellbores. In a drilling and measurement system asshown in FIG. 1, a wellbore 111 may be formed in subsurface formationsby rotary drilling in a manner that is well known to those skilled inthe art. Although the wellbore 111 in FIG. 1 is shown as being drilledsubstantially straight and vertically, some embodiments may bedirectionally drilled, i.e. along a selected trajectory in thesubsurface.

A drill string 112 is suspended within the wellbore 111 and has a bottomhole assembly (BHA) 151 which includes a drill bit 155 at its lower(distal) end. The surface portion of the drilling and measurement systemincludes a platform and derrick assembly 153 positioned over thewellbore 111. The platform and derrick assembly 153 may include a rotarytable 116, kelly 117, hook 118 and rotary swivel 119 to suspend, axiallymove and rotate the drill string 112. In a drilling operation, the drillstring 112 may be rotated by the rotary table 116 (energized by meansnot shown), which engages the kelly 117 at the upper end of the drillstring 112. Rotational speed of the rotary table 116 and correspondingrotational speed of the drill string 112 may be measured un a rotationalspeed sensor 116A, which may be in signal communication with a computerin a surface logging, recording and control system 152 (explainedfurther below). The drill string 112 may be suspended fin the wellbore111 from a hook 118, attached to a traveling block (also not shown),through the kelly 117 and a rotary swivel 119 which permits rotation ofthe drill string 112 relative to the hook 118 when the rotary table 116is operates. As is well known, a top drive system (not shown) may beused in other embodiments instead of the rotary table 116, kelly 117 andswivel rotary 119.

Drilling fluid (“mud”) 126 may be stored in a tank or pit 127 disposedat the well site. A pump 129 moves the drilling fluid 126 to from thetank or pit 127 under pressure to the interior of the drill string 112via a port in the swivel 119, which causes the drilling fluid 126 toflow downwardly through the drill string 112, as indicated by thedirectional arrow 158. The drilling fluid 126 travels through theinterior of the drill string 112 and exits the drill string 112 viaports in the drill bit 155, and then circulates upwardly through theannulus region between the outside of the drill string 112 and the wallof the borehole, as indicated by the directional arrows 159. In thisknown manner, the drilling fluid lubricates the drill bit 155 andcarries formation cuttings created by the drill bit 155 up to thesurface as the drilling fluid 126 is returned to the pit 127 forcleaning and recirculation. Pressure of the drilling fluid as it leavesthe pump 129 may be measured by a pressure sensor 158 in pressurecommunication with the discharge side of the pump 129 (at any positionalong the connection between the pump 129 discharge and the upper end ofthe drill string 112). The pressure sensor 158 may be in signalcommunication with a computer forming part of the surface logging,recording and control system 152, to be explained further below.

The drill string 112 typically includes a BHA 151 proximate its distalend. In the present example embodiment, the BHA 151 is shown as having ameasurement while drilling (MWD) module 130 and one or more loggingwhile drilling (LWD) modules 120 (with reference number 120A depicting asecond LWD module 120). As used herein, the term “module” as applied toMWD and LWD devices is understood to mean either a single instrument ora suite of multiple instrument contained in a single modular device. Insome embodiments, the BHA 151 may include a rotary steerable directionaldrilling system (RSS) and hydraulically operated drilling motor of typeswell known in the art, collectively shown at 150 and the drill bit 155at the distal end.

The LWD modules 120 may be housed in one or more drill collars and mayinclude one or more types of well logging instruments. The LWD modules120 may include capabilities for measuring, processing, and storinginformation, as well as for communicating with the surface equipment. Byway of example, the LWD module 120 may include, without limitation oneof a nuclear magnetic resonance (NMR) well logging tool, a nuclear welllogging tool, a resistivity well logging tool, an acoustic well loggingtool, or a dielectric well logging tool, and so forth, and may includecapabilities for measuring, processing, and storing information, and forcommunicating with surface equipment, e.g., the surface logging,recording and control unit 152.

The MWD module 130 may also be housed in a drill collar, and may containone or more devices for measuring characteristics of the drill string112 and drill bit 155. In the present embodiment, the MWD module 130 mayinclude one or more of the following types of measuring devices: aweight-on-bit (axial load) sensor, a torque sensor, a vibration sensor,a shock sensor, a stick/slip sensor, a direction measuring device, andan inclination and geomagnetic or geodetic direction sensor set (thelatter sometimes being referred to collectively as a “D&I package”). TheMWD module 130 may further include an apparatus (not shown) forgenerating electrical power for the downhole system. For example,electrical power generated by the MWD module 130 may be used to supplypower to the MWD module 130 and the LWD module(s) 120. In someembodiments, the foregoing apparatus (not shown) may include aturbine-operated generator or alternator powered by the flow of thedrilling fluid 126. It is understood, however, that other electricalpower and/or battery systems may be used to supply power to the MWDand/or LWD modules.

In the present example embodiment, the drilling and measurement systemmay include a torque sensor 159 proximate the surface. The torque sensor159 may be implemented, for example in a sub 160 disposed proximate thetop of the drill string 112, and may communicate wirelessly to acomputer (see FIG. 11) in the surface logging, recording and controlsystem 152, explained further below. In other embodiments, the torquesensor 159 may be implemented as a current sensor coupled to an electricmotor (not shown) used to drive the rotary table 116. In the presentexample embodiment, an axial load (weight) on the hook 118 may bemeasured by a hookload sensor 157, which may be implemented, forexample, as a strain gauge. The sub 160 may also include a hookelevation sensor 161 for determining the elevation of the hook 118 atany moment in time. The hook elevation sensor 161 may be implemented,for example as an acoustic or laser distance measuring sensor.Measurements of hook elevation with respect to time may be used todetermine a rate of axial movement of the drill string 112. The hookelevation sensor may also be implemented as a rotary encoder coupled toa winch drum used to extend and retract a drill line used to raise andlower the hook (not shown in the Figure for clarity). Uses of such rateof movement, rotational speed of the rotary table 116 (or,correspondingly the drill string 112), torque and axial loading (weight)made at the surface and/or in the MWD module 130 may be used in one morecomputers as will be explained further below.

The operation of the MWD and LWD instruments of FIG. 1 may be controlledby, and sensor measurements from the various sensors in the MWD and LWDmodules and the other sensors disposed on the drilling and measurementunit described above may be recorded and analyzed using the surfacelogging, recording and control system 152. The surface logging,recording and control system 152 may include one or more processor-basedcomputing systems or computers. In the present context, a processor mayinclude a microprocessor, programmable logic devices (PLDs), field-gateprogrammable arrays (FPGAs), application-specific integrated circuits(ASICs), system-on-a-chip processors (SoCs), or any other suitableintegrated circuit capable of executing encoded instructions stored, forexample, on tangible computer-readable media (e.g., read-only memory,random access memory, a hard drive, optical disk, flash memory, etc.).Such instructions may correspond to, for instance, workflows and thelike for carrying out a drilling operation, algorithms and routines forprocessing data received at the surface from the BHA 155 (e.g., as partof an inversion to obtain one or more desired formation parameters), andfrom the other sensors described above associated with the drilling andmeasurement system. The surface logging, recording and control system152 may include one or more computer systems as will be explained withreference to FIG. 11. The other previously described sensors includingthe torque sensor 159, the pressure sensor 158, the hookload sensor 157and the hook elevation sensor 161 may all be in signal communication,e.g., wirelessly or by electrical cable with the surface logging,recording and control system 152. Measurements from some of theforegoing sensors and some of the sensors in the MWD and LWD modules maybe used in various embodiments to be further explained below.

1. General Description of Methods

A Guidance and Statistical Processing Method according to the presentdisclosure may operate with, for example, two levels of granularity: ona stand by stand (or joint by joint) basis and for an entire trip (i.e.,a complete removal from or insertion into the wellbore of a drill stringas set forth in the Background section herein). Different users of themethod and system may use different levels of granularity. For example,the Driller (drilling unit operator) is likely to be interested in standby stand information, while the wellbore operator or wellbore designeris more likely to be interested in the overall trip information.

It will be appreciated by those skilled in the art that trippingoperations are most commonly conducted by assembling or disassemblingmultiple segment assemblies, typically each consisting of three segmentsor joints of drill pipe and/or drill collars, heavy weight drill pipeand/or drilling tools. Each such multiple segment assembly is referredto as a stand. It should be clearly understood that while the presentdescription is made in terms of stands, the use of the methods describedherein is not limited to tripping by stands. The methods are equallyapplicable to single joints or stands having more or fewer than threesegments (joints) of the above described items.

While tripping a joint or stand, the Guidance and Statistical ProcessingMethod according to the present disclosure calculatesacceleration/deceleration and maximum speed within a selected window orrange to either trip in or out of the well without incurringcorresponding surge or swab effects or damaging shock and vibrationeffects. The acceleration/deceleration and maximum speed may bepresented to the drilling crew as an idealized target speed profile overtime for tripping a particular stand. Such idealized speed profile maythen be compared to an actual speed profile obtained by the drillingcrew operating the drilling unit, both while and after tripping theparticular stand, so that the drilling crew can observe how well theirperformance matches the idealized speed profile in order to makeadjustments so that they improve or maintain performance within aso-called “fast and safe” operating range. Fast and safe in the presentcontext may be used to mean the highest acceleration/speed that may beattained without risk of swab or surge, within a preselected error ofuncertainty range. While tripping, the system may display indicators asto when to speed up or slow down movement of the drill string to meetthe idealized speed profile. Additionally, the system may generate analert (visual, audible or otherwise) when predetermined swab or surgeconditions or excessive shock and vibration conditions have been met andmay provide indication how to mitigate the foregoing alerted conditions.Performance measures of the actual pipe movement may be calculated withrespect to the idealized speed profile and occurrence of actual swab andsurge and excessive shock and vibration events. Connection time (amountof time used to assemble or disassemble one joint or stand of pipe fromthe drill string) performance may also be measured and presented alongwith an expected connection time profile.

For an entire trip, the Guidance and Statistical Processing Methodaccording to the present disclosure may calculate a target average speedprofile to be attained at each point in the wellbore (according to drillbit depth). The target average speed profile may represent an idealspeed profile so as to trip the pipe as fast as possible withoutincurring dangerous (e.g., swab or surge) conditions and may alsoaccount for target connection time, acceleration/deceleration, and speedconstraints that avoid swab and surge effects and shock and vibrationeffects. Performance measures may be calculated with respect to theidealized profile and actual swab and surge and shock and vibrationevents. Actual connection time performance may also be tracked andpresented against a predetermined target connection time performance.

In another aspect, a schedule forecast may project delay/advance ofother planned drilling activities based on current well state andforecast completion time for the current activity based on currentperformance calculated as described above. For example, trippingcompletion may be forecast based on current progress and projections ofthe current tripping performance to the end of the trip. Additionally,drilling completion may be forecast based on current drilling progressand projections of the current drilling performance to the end of thecurrent wellbore section. These projections may be adjusted by forecastlimits or changing conditions.

2. Description of an Example Implementation

FIG. 2 shows a block diagram illustrating an example process by whichthe present method may provide acceleration/deceleration and speedtarget profiles for a stand of the drill string. The swab and surgeacceleration and speed range calculations may use the following inputparameters, as shown at 10 in FIG. 1:

-   a) Length, size, unit weight of drill pipe-   b) Length, size, unit weight of the drill collars-   c) Wellbore diameter (drill bit size)-   d) Drilling Fluid viscosity and gel strength;-   e) Drilling Fluid density    Any value changes in Drilling Fluid parameters (e.g., viscosity, gel    strength, density) may require recalculation of surge and swab    acceleration and speed ranges. The other values may be expected not    to change during any single trip in or out of the wellbore.

Additional, optional inputs, also shown at 10, to the swab and surgecalculations may enable more accurate acceleration and speed rangecalculations. Examples of such additional inputs may include, withoutlimitation:

-   f) Inclination, azimuth, curvature of the wellbore-   g) Heavy weight drill pipe included in the drill string-   h) Bottom hole assembly (BHA) component sizes and weights,    stabilizer locations, drill bit configuration-   i) Drilling Fluid parameters at with respect to temperature-   j) Wellbore temperature with respect to depth-   k) Measured or offset Formation data

The swab and surge calculation may use the foregoing inputs to calculatea drill string speed and acceleration at each depth in the wellbore suchthat swab and surge and/or excessive shock and vibration events arelikely to occur. Swab and surge calculation techniques using any or allof the forgoing inputs are known in the art. Shock and vibrationcalculation techniques using any or all of the foregoing inputs are alsoknown in the art. The foregoing calculation results in a maximum safepipe movement speed with respect to depth. The “Calculate Speed Profile”calculation, shown at 12, calculates the speed at each bit depth for thestand that would induce a swab or surge pressure, or induce excessiveshock and vibration. The Ideal Speed Profile may be the lower of theswab/surge inducing speed and the excessive shock and vibration speedprofile minus a safety factor that ensures that the maximum drill stringspeed is as fast as possible without incurring the stated adverseconditions. The safety factor may be determined in a number of differentways, the simplest way being user preference. The Ideal Speed profilemay be displayed as a band or range of speeds from the maximum safemovement speed to the maximum safe movement speed less the safetymargin.

As a stand is tripped, the measured pipe movement speed, from beginningof drill string movement to cessation thereof, may be compared to theideal speed profile, as shown at 14. Drill string movement speed may bemeasured by suitable sensors that measure, e.g., height (i.e., verticalposition) of a swivel or top drive above the drill floor, wherein suchmeasurements of position made with respect to time may be converted toindication of speed. Such sensors are well known in the art. The depthof the drill string in the wellbore is generally calculated by thelength of the assembled drill string components less the measured swivelor top drive height above the drill floor. Speed may be inferred, asexplained above, by using the height measurement with respect to time,or may be measured directly by different types of sensors, for example,rotary encoders that measure rotational speed of a winch drum used toextend and retract a drill line used to raise and lower the swivel ortop drive (which rotation speed will be related to vertical movementspeed of the swivel or top drive). The foregoing information may beentered into a computer and display system which will be described inmore detail with reference to FIG. 13.

When the actual drill string speed with respect to the ideal speed isoutside of a “Fast and Safe” operating envelope (i.e., the abovedescribed speed range), an indicator may be displayed to the user tospeed up or slow down longitudinal movement of the drill string in orderto adjust the speed to be within the “Fast and Safe” operating range.FIG. 2 shows a graphic example of how the “Fast and Safe” operatingrange 18 may be presented to the user and how the actual drill stringmovement speed, shown at curve 16, may be displayed along with the Fastand Safe operating range 18.

FIGS. 4A and 4B show various examples of display of condition indicatorswhen the actual speed of the drill string is outside the Fast and Safeoperating range (18 in FIG. 3). For example, a color or otherwise codedsegment of the speed curve may be displayed, as in FIG. 4B, and awarning or other alert text box 19 may be displayed as shown in FIG. 4A.The text box 19 shown in FIG. 4A may also provide an instruction to theuser, e.g., the drilling unit operator, an amount by which to change thedrill string movement speed, e.g. as a numerical display 19A in units ofspeed to return the drill string speed to within the “Fast and Safe”range (18 in FIG. 2).

The comparison (14 in FIG. 2) between the ideal speed profile and theactual speed profile may also be used to generate in the computer system(FIG. 13) performance statistics that may be recorded and optionallyreported to appropriate personnel, e.g., the wellbore operator and/orthe drilling unit operator. The calculated and/or reported statisticsinclude may the fraction (e.g., expressed in percentage) of the totaltime that the speed for the stand, and for the entire pipe trip thatare:

-   a) Fast and Safe-   b) Too Fast (above the “Fast and Safe” operating envelope)-   c) Too Slow (below the “fast and safe” operating envelope-   d) Generate Swab/Surge conditions-   e) Generate excessive Shock and Vibration conditions    Additionally, the calculated statistics may show the number and the    percentage of stands or fractions thereof that have been moved:-   a) fully “fast & safe”-   b) too fast or too slow, in whole or in part-   c) with swab or surge conditions-   d) with shock and vibration conditions-   e) fraction too fast which is calculated by comparing the total time    to trip the stand to the ideal time if it were tripped in a “fast &    safe” manner-   f) fraction too slow which is calculated by comparing the total time    to trip the stand to the ideal time if it were tripped in a “fast &    safe” manner-   g) number of times swab or surge conditions were incurred-   h) number of times shock and vibration conditions were incurred-   i) relative overall speed from stand to stand

An example of such statistical displays is shown in FIGS. 5A and 5B.FIG. 5A shows cumulative trip information as above on a per-stand (orper-joint) basis. In some embodiments the display may show the sameinformation cumulatively for an entire trip. FIG. 5B shows the sameinformation for each individual stand in a particular trip in histogramformat. The information for individual stands may be color or otherwisecoded.

FIG. 6 shows a block diagram of an example process for calculating andcomparing an ideal trip time to an actual trip time. An ideal connectiontime (time to assemble a joint or stand or disassemble the same from thelength of drill string still in the wellbore) may be obtained fromseveral sources, for example:

-   a) user input-   b) average from offset wells-   c) average top quartile performance from offset wells-   d) best performance so far on current well-   e) average performance so far on current well

An aggregation process at 20 accepts as input the ideal connection timeand the ideal speed for each (joint or) stand)as calculated at 12 inFIG. 2) to create an ideal detailed speed profile for a particular drillstring trip.

An “Ideal Averaged Speed Profile for Trip” may be calculated, at 22,from the

“Ideal Detailed Speed profile for Trip” at 20. The actual averagingalgorithm may be selected from among a number of different algorithmsand is not intended to limit the scope of the present disclosure. Oneexample is a moving average with a window large enough to encompassexactly one connection. The purpose for calculating an average is toallocate the connection time across the entire trip time so that theindividual connection events need not be accounted for as discreteevents in the trip speed profile but are in fact accounted for in thetrip speed profile.

The “Actual Averaged Speed Profile for Trip” may be calculated using thesame averaging algorithm for actual measured connection times.

The Compare process element at 24 compares the ideal averaged trip speedprofile to the actual trip speed profile to provide substantiallyinstantaneous feedback to the drilling crew while tripping and tocalculate statistics. Alerts may be provided to the drilling crew withrespect to values outside the ideal speed profile range similar to thoseprovided as explained with reference to FIGS. 4A and 4B. For example:

-   a) Speed is slower than the “fast and safe” zone, please speed up.-   b) Speed is faster than the “fast and safe” zone, slow down now.-   c) Surge or Swab conditions have been met, slow down immediately.-   d) Excessive shock and vibration conditions have been met, slow down    immediately.

The statistics may be calculated at 26 in FIG. 6 and may be displayed asthe percentage of the time and the number of instances that the speedis:

-   a) within the “fast and safe” zone-   b) too fast-   c) too slow

The statistics calculation 26 may also include calculating andcommunicating the number and magnitude of any swab and surge events. Oneexample embodiment of displaying the calculations above is shown in FIG.7. A representation of the well and any intermediate casing depth isshown at 29. At 28 the ideal average speed profile for any trip may bedisplayed as a curve. At 30, the actual average speed may be displayedas a curve. A current value of the actual average speed may be displayedas a point at 31.

FIG. 8A shows a similar graph to that shown in FIG. 7, but further alongthe trip, and segments of the actual average speed curve which deviatefrom the ideal average range may be identified by color or other coding.FIG. 8B shows an example of a “pie chart” cumulative set of statisticscalculated using the same data used to calculate the graph of FIG. 8A.

FIG. 9 shows an example of using the calculations as explained withreference to FIG. 6, and displayed with reference to FIG. 8A to comparecurrent well performance to that of other (e.g., “offset” or nearby)wells. In each case, the ideal average trip speed may be normalized forfactors such as well depth, and the factors used to calculate the idealtrip speed range as explained with reference to FIG. 2. That is, eachwell, having its own unique parameters that govern the ideal trip speedrange, may have its ideal trip speed range (and correspondingly itsaverage ideal trip speed range) adjusted so that a comparison of idealtrip speed ranges is normalized across all compared wells. The actualaverage trip speed calculated as explained with reference to FIG. 6 maybe similarly normalized. Each well in the comparison may have itsnormalized actual average trip speed compared to the normalized idealtrip speed range as shown in FIG. 9. Deviations as explained withreference to FIGS. 7, 8A and 8B may be displayed in discrete form orcumulative form for evaluation purposes.

Referring to FIG. 10, the Guidance and Statistical Processing Methodaccording to the present disclosure may also compile individualconnection times statistics. Such statistics may be used to compare anddisplay information on actual connection time with respect topredetermined benchmarks, e.g., connection times from highly performingoffset wells or from theoretical ideal times calculated by measurementof connection procedure times under controlled conditions. Additionally,the computer system (FIG. 13) may collect and report connection timetrend information for subsets of all the individual connection times,such as whether or not connection time is increasing or decreasing,consistently within the benchmark range, consistently outside of thebenchmark range, etc. Various trend identification algorithms, forexample and without limitation, one described in U.S. Patent ApplicationPublication No. 2011/0220410 A1 filed by Aldred et al. may be used todetermine trends from discrete data points. The graph in FIG. 10illustrates a series of connection times with the trends identified at33, 35 and 37 using the foregoing described algorithm. The connectiontimes trended up for a while at 33, and exited the “Fast and Safe”connection time envelope, but then returned to the “fast and safe”envelope at 35 and are remained thereafter at 37 consistently withinthat envelope. The trending information may be recalculated at everyconnection point and presented to the appropriate personnel so thatsuitable actions may be undertaken to adjust the performance to remainwithin the target “Fast and Safe” envelope 39.

Referring to FIG. 11, a block diagram therein shows elements of anexample process to reschedule ancillary operations based on actualperformance during drilling and tripping on any particular wellbore. Theprimary input to the example process may be an output from a drillingplan, which may be generated by the wellbore designer. The drilling planmay be the original drilling plan or a revised drilling plan. A drillingplan is made up of a series of drilling and ancillary activities such asdrilling, tripping, casing, cementing, etc. Each activity will haveassociated therewith what action is to be performed and an associatedstart and stop time. For example, drilling from a first depth to asecond depth may expected to take a predetermined amount of time. Theoutput of the drilling plan may be converted into an initial scheduleof, e.g., forecast drilling times at block 32, forecast tripping times,at block 34 and forecast casing running at cementing times at block 36.The foregoing three activities shown in blocks 32, 34 and 36 are onlymeant to serve as examples and are not an exhaustive list of activitiesintended to limit the scope of activities according to the presentdisclosure. The drilling plan may provide not only an amount of timeexpected to be used in the performance of each activity, but also thesequence in which the activities are to occur, thus enabling estimatingan initial start and stop time for each activity. An example of adrilling plan compared to actual performance is described in U.S. PatentNo. 6,233,498 issued to King et al.

Each activity 32, 34, 36 will have a forecasting procedure applied to itthat takes into account the original drilling plan data and the currentprogress of each activity with respect to the original drilling plan.Each activity may optionally have a target speed profile for thatparticular activity. The forecasting procedure may use the currentprogress and current speed of each activity to estimate when theparticular activity is likely to be complete. The overall drilling plan,i.e., the forecast start and stop times, may be adjusted (either delayedor advanced) based on the completion time estimates for each activity.Forecast start and stop times may be based on a number of criteria, forexample:

-   a) equal the plan when activity has not yet begun or is proceeding    according to plan-   b) be calculated from offset well data based on the activity speed    on similar wells-   c) be recalculated from the original plan by using the current    performance to predict when the activity will complete if the    current performance is maintained. be calculated by using planned    performance from this point to predict when the activity will    complete.

The schedule forecasting activity may be updated continuously or ondemand before or after drilling in order to have a better understandingof when activities are likely to begin and end so that logistics may beplanned. The process may be applied to the original drilling plan or anyrevised drilling plans.

FIG. 12 displays one example of how the Schedule Forecast may berepresented. The representation in FIG. 12 compares a planned time vsdepth curve 40 to a forecast (updated based on actual rig activitytimes) time vs depth curve 42. The Schedule Forecast may also berepresented, for example, as a Gantt chart. The output is a forecastwell activity plan with revised estimates for the start and completiontime for all uncompleted/subsequent activities in the drilling plan. Theforegoing may be displayed on a well section basis, a specified timehorizon basis, or for the remainder of the well. It may optionally becascaded to a subsequent well planned to be drilled by the same drillingunit.

FIG. 13 shows an example computing system 100 in accordance with someembodiments. The computing system 100 may be an individual computersystem 101A or an arrangement of distributed computer systems. Thecomputer system 101A may include one or more analysis modules 102 thatmay be configured to perform various tasks according to someembodiments, such as the tasks depicted in FIGS. 4A, 4B, 5, 7, 7, 8A,8B, and 9 through 12. To perform these various tasks, analysis module102 may execute independently, or in coordination with, one or moreprocessors 104, which may be connected to one or more storage media 106.The processor(s) 104 may also be connected to a network interface 108 toallow the computer system 101A to communicate over a data network 110with one or more additional computer systems and/or computing systems,such as 101B, 101C, and/or 101D (note that computer systems 101B, 101Cand/or 101D may or may not share the same architecture as computersystem 101A, and may be located in different physical locations, forexample, computer systems 101A and 101B may be at the well drillinglocation, while in communication with one or more computer systems suchas 101C and/or 101D that may be located in one or more data centers onshore, aboard ships, and/or located in varying countries on differentcontinents).

A processor can include a microprocessor, microcontroller, processormodule or subsystem, programmable integrated circuit, programmable gatearray, or another control or computing device.

The storage media 106 may be implemented as one or morecomputer-readable or machine-readable storage media. Note that while inthe example embodiment of FIG. 13 the storage media 106 are depicted aswithin computer system 101A, in some embodiments, the storage media 106may be distributed within and/or across multiple internal and/orexternal enclosures of computing system 101A and/or additional computingsystems. Storage media 106 may include one or more different forms ofmemory including semiconductor memory devices such as dynamic or staticrandom access memories (DRAMs or SRAMs), erasable and programmableread-only memories (EPROMs), electrically erasable and programmableread-only memories (EEPROMs) and flash memories; magnetic disks such asfixed, floppy and removable disks; other magnetic media including tape;optical media such as compact disks (CDs) or digital video disks (DVDs);or other types of storage devices. Note that the instructions discussedabove may be provided on one computer-readable or machine-readablestorage medium, or alternatively, can be provided on multiplenon-transitory computer-readable or machine-readable storage mediadistributed in a large system having possibly plural nodes. Suchcomputer-readable or machine-readable storage medium or media may beconsidered to be part of an article (or article of manufacture). Anarticle or article of manufacture can refer to any manufactured singlecomponent or multiple components. The storage medium or media can belocated either in the machine running the machine-readable instructions,or located at a remote site from which machine-readable instructions canbe downloaded over a network for execution.

It should be appreciated that computing system 100 is only one exampleof a computing system, and that computing system 100 may have more orfewer components than shown, may combine additional components notdepicted in the example embodiment of FIG. 13, and/or computing system100 may have a different configuration or arrangement of the componentsdepicted in FIG. 13. The various components shown in FIG. 13 may beimplemented in hardware, software, or a combination of both hardware andsoftware, including one or more signal processing and/or applicationspecific integrated circuits.

Further, the elements in the processing methods described above may beimplemented by running one or more functional modules in informationprocessing apparatus such as general purpose processors or applicationspecific chips, such as ASICs, FPGAs, PLDs, or other appropriatedevices. These modules, combinations of these modules, and/or theircombination with general hardware are all included within the scope ofthe present disclosure.

While the invention has been described with respect to a limited numberof embodiments, those skilled in the art, having benefit of thisdisclosure, will appreciate that other embodiments can be devised whichdo not depart from the scope of the invention as disclosed herein.Accordingly, the scope of the invention should be limited only by theattached claims.

What is claimed is:
 1. A method for scheduling wellbore constructionactivities, comprising: entering a well plan into a computer, the wellplan comprising estimated start and stop times for a plurality ofactivities in a predetermined sequence; measuring progress of selectedones of the plurality of activities during their performance; in thecomputer, recalculating expected ending time of at least one of theplurality of activities based on progress thereof during the at leastone of the plurality of activities; in the computer, recalculatingexpected start and stop times for each activity subsequent to theactivity in progress based on the recalculated expected ending time; anddisplaying the recalculated start and stop times for each subsequentactivity.
 2. The method of claim 1 wherein the recalculated expectedending time comprises end of tripping time recalculated based on speedof at least a portion of a tripping activity.
 3. The method of claim 1wherein the recalculated expected ending time comprises end of wellboredrilling.
 4. The method of claim 1 wherein the recalculated expectedending time comprises using planned performance from the currentmeasurements to predict when the activity will complete.
 5. The methodof claim 1 wherein the recalculated expected ending time comprises usinga current speed projected to an end of a current activity.
 6. The methodof claim 1 wherein the recalculated expected ending time comprises usinga calculated maximum safe pipe movement speed to the end of a currentactivity.
 7. The method of claim 1 wherein the displaying comprisesgenerating a time chart with respect to depth of the wellbore segmentedinto time segments allocated to each activity.
 8. The method of claim 1wherein the displaying comprises generating a Gantt chart.
 9. The methodof claim 1 wherein the recalculated expected ending time comprises usinganalogous information from offset well data.
 10. A system for schedulingwellbore construction activities, comprising: a computer havingprogrammed therein a well plan, the well plan comprising estimated startand stop times for a plurality of activities in a predeterminedsequence; means for entering into the computer execution times andcompletion times of selected ones of the plurality of activities duringtheir performance, wherein the computer is programmed to recalculateexpected ending time of at least one of the plurality of activitiesbased on progress thereof during the at least one of the plurality ofactivities, the computer programmed to recalculate expected start andstop times for each activity subsequent to the activity in progressbased on the recalculated expected ending time; and a display in signalcommunication with the computer for displaying the recalculated startand stop times for each subsequent activity to a user.
 11. The system ofclaim 10 wherein the recalculated expected ending time comprises end oftripping time recalculated based on speed of at least a portion of atripping activity.
 12. The system of claim 10 wherein the recalculatedexpected ending time comprises end of wellbore drilling.
 13. The systemof claim 10 wherein the recalculated expected ending time comprisesusing planned performance from the current measurements to predict whenthe activity will complete.
 14. The system of claim 10 wherein therecalculated expected ending time comprises using a current speedprojected to an end of a current activity.
 15. The system of claim 10wherein the recalculated expected ending time comprises using acalculated maximum safe pipe movement speed to the end of a currentactivity.
 16. The system of claim 10 wherein the computer is programmedto transmit to the display a time chart with respect to depth of thewellbore segmented into time segments allocated to each activity. 17.The system of claim 10 wherein the computer is programmed to transmit tothe display a Gantt chart.
 18. The system of claim 10 wherein therecalculated expected ending time comprises using analogous informationfrom offset well data.